From 5848ee74fac4055966df7c8f7f2e9529251fd8f4 Mon Sep 17 00:00:00 2001
From: bangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 12 May 2008 21:07:27 +0000
Subject: [PATCH] Implement FunctionParser::default_variable_names

git-svn-id: https://svn.dealii.org/trunk@16083 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/base/include/base/function_parser.h | 35 ++++++++++++++++++++-
 deal.II/doc/news/changes.h                  |  6 ++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/deal.II/base/include/base/function_parser.h b/deal.II/base/include/base/function_parser.h
index 851c16e263..7a754ed495 100644
--- a/deal.II/base/include/base/function_parser.h
+++ b/deal.II/base/include/base/function_parser.h
@@ -384,7 +384,19 @@ class FunctionParser : public Function<dim>
                      const ConstMap    &constants,
                      const bool time_dependent = false,
                      const bool use_degrees = false);
-  
+
+				     /**
+				      * A function that returns
+				      * default names for variables,
+				      * to be used in the first
+				      * argument of the initialize()
+				      * functions: it returns "x" in
+				      * 1d, "x,y" in 2d, and "x,y,z"
+				      * in 3d.
+				      */
+    static
+    std::string
+    default_variable_names ();
 
 				     /**
 				      * Return the value of the
@@ -459,6 +471,27 @@ class FunctionParser : public Function<dim>
     unsigned int n_vars;
 };
 
+
+template <int dim>
+std::string
+FunctionParser<dim>::default_variable_names ()
+{
+  switch (dim)
+    {
+      case 1:
+	    return "x";
+      case 2:
+	    return "x,y";
+      case 3:
+	    return "x,y,z";
+      default:
+	    Assert (false, ExcNotImplemented());
+    }
+  return "";
+}
+
+	    
+
 DEAL_II_NAMESPACE_CLOSE
 
 #endif
diff --git a/deal.II/doc/news/changes.h b/deal.II/doc/news/changes.h
index cb8cbe9164..9e4e55e299 100644
--- a/deal.II/doc/news/changes.h
+++ b/deal.II/doc/news/changes.h
@@ -147,6 +147,12 @@ inconvenience this causes.
 <h3>base</h3>
 
 <ol>
+<li> <p> New: The FunctionParser::default_variable_names() function returns
+default names for variables in the given space dimension. For example, in
+2d, this would be "x,y".
+<br>
+(WB 2008/05/12)
+</p> </li>
 
 <li> <p>New: ConvergenceTable::evaluate_convergence_rates has been incomplete
 for a long time. An implementation for reduction_rate and 
-- 
2.39.5